Granitic igneous rocks are light colored rocks of a low density. Granitic magma is thick and stiff and contains a lot of silicon and oxygen. Granitic magma can build up a great deal of pressure, which is released during violent volcanic eruptions.
If you are referring to igneous rocks, they are classified as mafic.
Dark igneous rocks usually have higher amounts of heavier elements such as iron. Light-colored igneous rocks tend to be richer in lighter elements like sodium and aluminum.
Dense. Light colored igneous rocks have lower density compared to dark colored igneous rocks due to their higher silica content, which results in slower cooling and the formation of larger crystals.
Light-coloured igneous rocks, such as granite, have a higher silica content and lower iron and magnesium than darker ones, such as basalt. Since iron and magnesium are very dense minerals, this makes darker igneous rocks more dense than lighter ones.
Light colored igneous rock is called felsic, and is high in quartz, muscovite mica, and orthoclase feldsparcontent. Dark colored igneous rock is called mafic, and contains a lesser amount of silica along with olivine, pyroxene, amphibole, biotite mica, and plagioclase feldspar.
igneous
Normally, light colored igneous rocks are less dense compared to dark colored igneous rocks. This is because the light colored rocks have a less iron in them.
less dense
If you are referring to igneous rocks, they are classified as mafic.
Normally, light colored igneous rocks are less dense compared to dark colored igneous rocks. This is because the light colored rocks have a less iron in them.
Most dark-colored igneous rocks are mafic, which means they are rich in minerals like pyroxene, olivine, and amphibole. These minerals give the rocks their dark color due to higher iron and magnesium content. Additionally, dark-colored igneous rocks are typically extrusive, forming from rapid cooling at the Earth's surface.
Dark colored rocks.
The dark-colored igneous rock rich in iron and magnesium is called basalt. Basalt is a fine-grained rock that is commonly found in volcanic areas and oceanic crust. It is characterized by its dark color due to the presence of minerals like pyroxene and olivine.
Mafic igneous rocks, like basalt, are dark colored and low in silica.
As a first approximation, the colour of igneous rocks gives an estimate of the concentration of iron in it. Very dark igneous rocks commonly a large fraction of minerals with iron as a major constituent. As those minerals are denser than most other silicate minerals occuring in igneous rocks, dark colored igenous rocks are usually denser than the ligher ones.
Most dark-colored igneous rocks have a high density.
The dark colored mica is called biotite. It is a common mineral found in igneous and metamorphic rocks and is known for its dark brown to black color.